TABLE 2.

Pressure-mediated inactivation, membrane permeabilization to PI, and structural changes in E. coli K12TG1 cells by HHP treatments at 250 MPa for 0 and 10 min at +25°C and −20°C^a

Treatment conditions	% of cells with:		% Permeability to PI (±SE)		% Inactivation (inactivation in Dlog units ± SE)
	Condensed nucleoids	Aggregated proteins	Reversible	Irreversible
250 MPa at +25°C
0 min	94	14	6 ± 2	9 ± 2	77.61 (−0.65 ± 0.25)
10 min	96	88	16 ± 5	16 ± 3	93.24 (−1.17 ± 0.26)
250 MPa at −20°C
0 min	95	00	23 ± 5	11 ± 2	96.28 (−1.43 ± 0.29)
10 min	92	96	37 ± 5	15 ± 3	99.96 (−3.41 ± 0.25)

^aStructural changes were examined by TEM, and fixation was performed under pressure. The percentages of affected cells were calculated with respect to the total number of cells examined for each TEM micrograph (at least 300 cells).